Page:Scientific results HMS Challenger vol 18 part 1.djvu/902

694 as the shell. Spiral turnings simple, all nearly of the same breadth and scarcely broader than the simple spherical medullary shell.

Dimensions.—Length of the cortical shell (with six spiral convolutions) 0.15, breadth 0.13; diameter of the medullary shell 0.012.

Habitat.—Mediterranean, Messina, Haeckel, surface; Atlantic, Stations 348 to 353, surface.

2. Lithelius primordialis, R. Hertwig.

Lithelius primordialis, R. Hertwig, 1879, Organism. d. Radiol., p. 54, Taf. vi. figs. 4, 4a.

Cortical shell subspherical, covered with numerous simple, bristle-shaped radial spines, longer than the shell. Spiral turnings simple, with gradually increasing breadth, so that the beginning of the third spiral is twice as broad as the first and as the simple spherical medullary shell.

Dimensions.—Diameter of the cortical shell (with two spiral convolutions) 0.12; diameter of the medullary shell 0.02.

Habitat.—Mediterranean, Messina, R. Hertwig, surface.

3. Lithelius alveolina, Haeckel, 1862.

Lithelius alveolina, Haeckel, 1862, Monogr. d. Radiol., p. 520, Taf. xxvii. figs. 8, 9.

Cortical shell spherical, covered with simple, very numerous (two hundred to three hundred or more), short, bristle-shaped radial spines, scarcely half as long as the radius of the shell. Spiral turnings simple, with gradually increasing breadth, so that the beginning of the third spiral is three times as broad as the first and as the simple spherical medullary shell.

Dimensions.—Diameter of the cortical shell (with four spiral convolutions) 0.2; diameter of the medullary shell 0.01.

Habitat.—Cosmopolitan; Mediterranean, Atlantic, Pacific, on many Stations, surface.

4. Lithelius capreolus, n. sp.

Cortical shell lentelliptical, one and a fourth times as long as broad, covered with numerous (eighty to one hundred and twenty or more) short, branched radial spines, about half as long as the radius of the shell; each spine once or twice dichotomous, with curved divergent branches. Spiral turnings simple, with gradually increasing breadth, so that the beginning of the third spiral is twice as broad as the first, and as the simple spherical medullary shell.

Dimensions.—Length of the cortical shell (with four spiral convolutions) 0.18, breadth 0.14; diameter of the medullary shell 0.015.

Habitat.—Pacific, central area, Station 274, surface.

Definition.—Spiral convolutions of the cortical shell double.